AP BIOLOGY

Detailed explanation-1: -Blood enters the glomerulus at a fast rate through afferent arteriole with greater diameter and drains way by efferent arteriole with smaller diameter at slower rate. This creates hydrostatic pressure within glomerulus.

Detailed explanation-2: -Afferent arteriole brings blood towards the glomerulus. Blood from the glomerulus is carried away by an efferent arteriole. The pressure exerted by blood (hydrostatic pressure) in afferent arteriole is +75 mm.

Detailed explanation-3: -The main reason that the hydrostatic pressure stays high in the glomerular capillaries is that they don’t coalesce into a vein but rather into an arteriole. The efferent arterioles are high-pressure vessels with muscular walls just like the afferent arterioles.

Detailed explanation-4: -The myogenic response is the reflex response of the afferent arterioles to changes in blood pressure. Increased blood pressure increases the tension in the vascular wall, and the vascular smooth muscle contracts. Similarly, decreased blood pressure decreases the tension and the smooth muscle relaxes.